1. Field of the Invention
A dual display module which is slim and has enhanced impact resistance and a display apparatus having the dual display module.
2. Description of the Related Art
Recently, display apparatuses capable of replacing the cathode-ray tube (CRT) displays have been developed. Examples of such display apparatuses are the liquid crystal display (LCD), the field emission display (FED), the plasma display panel (PDP), the electro-luminescence (EL) display device, and the like. From among the above, the PDP is highlighted since the PDP has a simple structure and a simple manufacturing process, and is the most appropriate display apparatus that has a large screen. However, the PDP is disadvantageous because of its low luminous efficiency, low luminance, and high power consumption. In contrast, an active matrix LCD (AMLCD), having thin film transistors (TFTs), is manufactured by a semiconductor device technique, and thus the AMLCD is disadvantageous for a large screen. However, since notebook computers commonly adopt the AMLCD as a display device, there is an increasing demand for the AMLCD. But AMLCD is also disadvantageous in that it is difficult to design and make a large screen AMLCD, and the AMLCD requires a high power consumption due to a backlight unit. Also, the AMLCD has many optical losses due to the presence of optical devices such as a polarized light filter, a prism sheet, a diffusion plate, and the like, and the AMLCD also has a narrow viewing angle.
In contrast, the EL display device is largely divided into an inorganic EL device and an organic EL device, according to materials used for the emission layer. The EL display device is a self light-emitting device and is advantageous for its fast response time, high luminous efficiency, high luminance, and wide view-angle. From among such EL display devices, the organic light emitting diode (OLED), that is the EL display device using organic materials, is advantageous due to its low direct-current (DC) driving voltage, its thinning probability, its uniformity of emitted light, its easy pattern forming, its high luminous efficiency, its full color emission in a visible ray region, and the like. As a result, the OLED is a technology field that is actively being developed.
Such an OLED is divided into a bottom-emission type and a top-emission type, according to the light emitting direction. Also, the OLED is divided into a passive matrix OLED (PMOLED) and an active matrix OLED (AMOLED), according to the driving method.
Recently, a dual display panel is used. The dual display panel has two OLED panels. An AMOLED may be disposed on one surface of the dual display panel and a PMOLED may be disposed on the other surface of the dual display panel. The dual display panel is used in mobile phones. In particular, with respect to the dual display panel used in a folder-type mobile phone, when a user folds the folder-type mobile phone, an OLED panel (e.g., the PMOLED) disposed on one surface of the dual display panel may be used, and when a user unfolds the folder-type mobile phone, an OLED panel (e.g., AMOLED) disposed on the other surface of the dual display panel may be used.